Teen violence linked to soda

2011-10-25 11:25

Paris - Researchers in the US said on Tuesday they had found a "shocking" association - if only a statistical one - between violence by teenagers and the amount of soda they drank.

High-school students in inner-city Boston who consumed more than five cans of non-diet, fizzy soft drinks every week were between 9% and 15% likelier to engage in an aggressive act compared with counterparts who drank less.

"What we found was that there was a strong relationship between how many soft drinks that these inner-city kids consumed and how violent they were, not only in violence against peers but also violence in dating relationships, against siblings," said David Hemenway, a professor at the Harvard School of Public Health.

"It was shocking to us when we saw how clear the relationship was," he said in an interview.

But he stressed that only further work would confirm - or disprove - the key question whether higher consumption of sweet sodas caused violent behaviour.

'Dose response'

The new study was based on answers to questionnaires filled out by 1 878 public-school students aged 14 to 18 in the inner Boston area, where Hemenway said crime rates were much higher than in the wealthier suburbs.

The overwhelming majority of respondents were Hispanic, African-American or mixed; few were Asian or white.

Among the questions were how much carbonated non-diet soft drink, measured in 355ml cans, the teens had drunk in the previous seven days.

They were also asked whether they drank alcohol or smoked, carried a weapon or showed violence towards peers, family members and partner.

What emerged, said Hemenway, was evidence of "dose response", in other words, the more soda was consumed, the likelier the tendency toward violence.

Among those who drank one or no cans of soft drink a week, 23% carried a gun or a knife; 15% perpetrated violence toward a partner; and 35% had been violent toward peers.

At the other end of the scale, among those who drank 14 cans a week, 43% carried a gun or a knife; 27% had been violent toward a partner; and more than 58% had been violent toward peers.

Aggressive behaviour

Overall, teens who were heavy consumers of sugary fizz were between 9% and 15% likelier to show aggressive behaviour compared with low consumers, even when ethnicity and other confounding factors were taken into account.

This is a magnitude similar to the link found, in previously researched, with alcohol or tobacco.

Hemenway said the study had included a couple of questions aimed at taking a children's home background into account, including whether the teen had taken a meal with his family in the previous days.

As it was only intended as a preliminary investigation, the questionnaire did not ask what kind of sodas the teens drank, he said.

"This is one of the very first studies to examine" the question, said Hemenway.

"We don't know why [there is this strong association]. There may be some causal effect but it's also certainly plausible that this is just a marker for other problems - that kids who are violent for whatever reason, they tend to smoke more, they tend to drink more alcohol and they tend to maybe drink more soft drinks. We just don't know.

"We want to look at it more carefully in following studies."

'Twinkie Defence'

The study, published in a British journal, Injury Prevention, will revive memories of the "Twinkie Defence", a US legal landmark in which a killer successfully argued that his behaviour had been swayed by eating junk food.

The defendant in this case, Dan White, had been charged with homicide. His lawyer's successful pleading led to conviction of a lesser charge, of voluntary manslaughter.

Several studies elsewhere have established a link between very high sugar consumption and lack of social bonding or irritable and anti-social behaviour.

Some diet research has also pointed the finger at the lack of micro-nutrients as a source of aggression, but this work is still in its early stages.

How about - Non-diet soda drinkers more likely to admit to carrying weapons to claim they are violent in anonymous surveys.

Leora - 2011-10-25 12:16

How about just accepting the fact that this behaviour is the result of poor parenting, and a general lethargy in applying some basic morals with regards to know right from wrong. This "discovery", just gives lazy parents ( and kids) another reason to shirk their responsibilites.

Bianca - 2011-10-25 14:43

... so true - never blame the parents. I think this is the most ridiculous thing I have ever heard! My 17 year old doesn't drink a lot of soda, because as a parent I tought him to go for the healthier options - soda and sweets should be seen is a "treat".

Mark - 2011-10-25 15:08

Watch how the tray of naartjies gets switched to fizzy drinks halfway through the next Schools Rugby tourney...

arielle.webster - 2011-10-25 21:25

Correlation doesn't imply causation. That's one of the first things they teach you in a statistics class. Just because you see a correlation between two things doesn't mean that one causes the other. If we flipped this argument the other way and said that violence causes a greater consumption of soda, it really doesn't make any sense at all. There is no controlled experiment here. Increased soda consumption is also linked closely to increased TV watching and video game playing. That doesn't mean drinking soda causes you to watch more TV or play more video games.
If an experiment were done where a random sample of students were put into groups such that students were given no soda, seven cans a week, and fourteen cans a week and violent behavior was monitored, then we can start making arguments. The correlation found from the current questionnaires may be a product of life-style or how the students were brought up. If you want to insist that it is the soda causing violent behavior, then do a true experiment.